Production of UV-B screens and changes in photosynthetic efficiency in Antarctic Nostoc commune colonies and a lichen Xanthoria elegans depend on a dose and duration of UV-B stress
The survival of non-vascular autotrophs in the extreme polar conditions and the principles of their high tolerance to extreme physical factors have been intriguing scientists in last decades. Therefore, this study focuses on the capacity of production of UV-B screening pigments in two model Antarcti...
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Online Access: | http://dx.doi.org/10.5817/cpr2015-1-6 https://journals.muni.cz/CPR/article/viewFile/12866/11200 |
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crmasarykunivpr:10.5817/cpr2015-1-6 2024-05-19T07:30:39+00:00 Production of UV-B screens and changes in photosynthetic efficiency in Antarctic Nostoc commune colonies and a lichen Xanthoria elegans depend on a dose and duration of UV-B stress Monteiro Estvāo, Diogo Miguel 2015 http://dx.doi.org/10.5817/cpr2015-1-6 https://journals.muni.cz/CPR/article/viewFile/12866/11200 unknown Masaryk University Press http://creativecommons.org/licenses/by-nc-nd/4.0 Czech Polar Reports volume 5, issue 1, page 55-68 ISSN 1805-0697 1805-0689 journal-article 2015 crmasarykunivpr https://doi.org/10.5817/cpr2015-1-6 2024-04-30T06:41:29Z The survival of non-vascular autotrophs in the extreme polar conditions and the principles of their high tolerance to extreme physical factors have been intriguing scientists in last decades. Therefore, this study focuses on the capacity of production of UV-B screening pigments in two model Antarctic species, one algal lichen, and colony of a cyanobacterium. Dose-dependent activation of protective mechanisms of Antarctic cyanobacterium (Nostoc commune) and algal lichen (Xanthoria elegans), synthesis of UV-B screening compounds in particular, were studied together with the changes in photosynthetic efficiency induced by a background photosynthetically active radiation (PAR) supplemented with UV-B radiation. The samples were exposed to different doses of UV-B (280–320 nm), low (0.7 W m-2), medium (1.5 W m-2) and high (3.0 W m-2) for 5 days. Untreated samples (control) were shielded from UV-B radiation during experiment. Chlorophyll fluorescence parameters and secondary UV-B protective metabolites were analysed in the intervals of 24 h, 48 h and 120 h. Amount of UV-B screening pigments was measured spectrophotometrically using several specific wavelengths in UV-B absorption range. Results showed that if exposed to a low dose of UV-B radiation or a short-term treatment, both species exhibited an increase in UV-B screening pigments to protect the lichen photobiont against UV-B damage. However, if exposed to a high dose of UV-B radiation or a long-term treatment, a decrease of UV-B screening compounds occured. This implies that Antarctic lichen and cyanobacterium can protect themselves against an increase of stress factors ranging within physiological limits, like e.g. increased synthesis of UV-B screening compounds thanks to a thinning of the ozone layer and consequent increase in UV radiation doses incident on Antarctic terrestrial ecosystems. Nevertheless, the likely increased UV-B radiation due to more intense depletion of stratospheric ozone layer may lead to alterations in UV-B tolerance in Antarctic lichens in ... Article in Journal/Newspaper Antarc* Antarctic Munipress - Masaryk University Press Czech Polar Reports 5 1 55 68 |
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Open Polar |
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Munipress - Masaryk University Press |
op_collection_id |
crmasarykunivpr |
language |
unknown |
description |
The survival of non-vascular autotrophs in the extreme polar conditions and the principles of their high tolerance to extreme physical factors have been intriguing scientists in last decades. Therefore, this study focuses on the capacity of production of UV-B screening pigments in two model Antarctic species, one algal lichen, and colony of a cyanobacterium. Dose-dependent activation of protective mechanisms of Antarctic cyanobacterium (Nostoc commune) and algal lichen (Xanthoria elegans), synthesis of UV-B screening compounds in particular, were studied together with the changes in photosynthetic efficiency induced by a background photosynthetically active radiation (PAR) supplemented with UV-B radiation. The samples were exposed to different doses of UV-B (280–320 nm), low (0.7 W m-2), medium (1.5 W m-2) and high (3.0 W m-2) for 5 days. Untreated samples (control) were shielded from UV-B radiation during experiment. Chlorophyll fluorescence parameters and secondary UV-B protective metabolites were analysed in the intervals of 24 h, 48 h and 120 h. Amount of UV-B screening pigments was measured spectrophotometrically using several specific wavelengths in UV-B absorption range. Results showed that if exposed to a low dose of UV-B radiation or a short-term treatment, both species exhibited an increase in UV-B screening pigments to protect the lichen photobiont against UV-B damage. However, if exposed to a high dose of UV-B radiation or a long-term treatment, a decrease of UV-B screening compounds occured. This implies that Antarctic lichen and cyanobacterium can protect themselves against an increase of stress factors ranging within physiological limits, like e.g. increased synthesis of UV-B screening compounds thanks to a thinning of the ozone layer and consequent increase in UV radiation doses incident on Antarctic terrestrial ecosystems. Nevertheless, the likely increased UV-B radiation due to more intense depletion of stratospheric ozone layer may lead to alterations in UV-B tolerance in Antarctic lichens in ... |
format |
Article in Journal/Newspaper |
author |
Monteiro Estvāo, Diogo Miguel |
spellingShingle |
Monteiro Estvāo, Diogo Miguel Production of UV-B screens and changes in photosynthetic efficiency in Antarctic Nostoc commune colonies and a lichen Xanthoria elegans depend on a dose and duration of UV-B stress |
author_facet |
Monteiro Estvāo, Diogo Miguel |
author_sort |
Monteiro Estvāo, Diogo Miguel |
title |
Production of UV-B screens and changes in photosynthetic efficiency in Antarctic Nostoc commune colonies and a lichen Xanthoria elegans depend on a dose and duration of UV-B stress |
title_short |
Production of UV-B screens and changes in photosynthetic efficiency in Antarctic Nostoc commune colonies and a lichen Xanthoria elegans depend on a dose and duration of UV-B stress |
title_full |
Production of UV-B screens and changes in photosynthetic efficiency in Antarctic Nostoc commune colonies and a lichen Xanthoria elegans depend on a dose and duration of UV-B stress |
title_fullStr |
Production of UV-B screens and changes in photosynthetic efficiency in Antarctic Nostoc commune colonies and a lichen Xanthoria elegans depend on a dose and duration of UV-B stress |
title_full_unstemmed |
Production of UV-B screens and changes in photosynthetic efficiency in Antarctic Nostoc commune colonies and a lichen Xanthoria elegans depend on a dose and duration of UV-B stress |
title_sort |
production of uv-b screens and changes in photosynthetic efficiency in antarctic nostoc commune colonies and a lichen xanthoria elegans depend on a dose and duration of uv-b stress |
publisher |
Masaryk University Press |
publishDate |
2015 |
url |
http://dx.doi.org/10.5817/cpr2015-1-6 https://journals.muni.cz/CPR/article/viewFile/12866/11200 |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Czech Polar Reports volume 5, issue 1, page 55-68 ISSN 1805-0697 1805-0689 |
op_rights |
http://creativecommons.org/licenses/by-nc-nd/4.0 |
op_doi |
https://doi.org/10.5817/cpr2015-1-6 |
container_title |
Czech Polar Reports |
container_volume |
5 |
container_issue |
1 |
container_start_page |
55 |
op_container_end_page |
68 |
_version_ |
1799488277810511872 |